eastern caldera margin fault. This uplift encompasses both Galán ignimbrite rocks but also parts of the basement, the latter especially in the southern part of the dome. Post-caldera volcanism occurred on the northern margin of the caldera 2.01 ± 0.28 million years ago, and several small ignimbrites were emplaced after the main Galán eruption until less than 2 million years ago. These ignimbrites have similar compositions to the Galán ignimbrite and were formed from magma left over by the main Galán eruption. The onset of resurgence within the caldera may have been triggered by the same magma that is responsible for the post-caldera volcanism along the eastern caldera rims. The post-caldera volcanic systems appear to be rather ill-defined, however. The most recent activity was of tectonic nature and consists of movements along the faults and mafic volcanism farther west. Seismic tomography indicates that there is still a melt zone under Galán, the "Cerro Galán Mush Body". See also Cerro Beltrán List of volcanoes in Argentina Notes References Bibliography Further reading Cerro Galan Caldera Oregon State University Cerro Galan Caldera, Argentina, from How Volcanoes Work, by Vic Camp, Department of Geological Sciences, San Diego State University Mountains of Argentina Volcanoes of Argentina Volcanoes of Catamarca Province Andean Volcanic Belt Calderas of Argentina VEI-8 volcanoes Supervolcanoes Volcanic crater lakes Polygenetic volcanoes Pliocene calderas Pleistocene calderas Pleistocene Argentina Puna de Atacama